Operators Everywhere

Fundamental to the OpenShift 4 platform is the concept of Operators. So far, we have used them without talking about why we need them and what they actually represent on a Kubernetes platform such as OpenShift. Let's cover this briefly without totally rewriting the book on the subject.23

At its heart, the Operator is a software pattern that codifies knowledge about the running and operation of a particular software application. That application could be a distributed key value store, such as etcd. It might be a web application such as the OpenShift web console. Fundamentally, the operator can represent any application domain that could be codified. A good analogy for an operator is the expert system, a rules-based bit of software that represents knowledge about a certain thing that is put to work in a meaningful way. If we take a database as an example, the Operator might codify what a real human database administrator does on a day-to-day basis, such as...